| Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize. | |
| | |
MedLine Citation:
|
PMID: 21402917 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Phytoalexins constitute a broad category of pathogen- and insect-inducible biochemicals that locally protect plant tissues. Because of their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses, which include insect-inducible monoterpene and sesquiterpene volatiles. Rice also produces a complex array of pathogen-inducible diterpenoid phytoalexins. Despite the demonstration of fungal-induced ent-kaur-15-ene production in maize over 30 y ago, the identity of functionally analogous maize diterpenoid phytoalexins has remained elusive. In response to stem attack by the European corn borer (Ostrinia nubilalis) and fungi, we observed the induced accumulation of six ent-kaurane-related diterpenoids, collectively termed kauralexins. Isolation and identification of the predominant Rhizopus microsporus-induced metabolites revealed ent-kaur-19-al-17-oic acid and the unique analog ent-kaur-15-en-19-al-17-oic acid, assigned as kauralexins A3 and B3, respectively. Encoding an ent-copalyl diphosphate synthase, fungal-induced An2 transcript accumulation precedes highly localized kauralexin production, which can eventually exceed 100 μg · g(-1) fresh weight. Pharmacological applications of jasmonic acid and ethylene also synergize the induced accumulation of kauralexins. Occurring at elevated levels in the scutella of all inbred lines examined, kauralexins appear ubiquitous in maize. At concentrations as low as 10 μg · mL(-1), kauralexin B3 significantly inhibited the growth of the opportunistic necrotroph R. microsporus and the causal agent of anthracnose stalk rot, Colletotrichum graminicola. Kauralexins also exhibited significant O. nubilalis antifeedant activity. Our work establishes the presence of diterpenoid defenses in maize and enables a more detailed analysis of their biosynthetic pathways, regulation, and crop defense function. |
| | |
Authors:
|
Eric A Schmelz; Fatma Kaplan; Alisa Huffaker; Nicole J Dafoe; Martha M Vaughan; Xinzhi Ni; James R Rocca; Hans T Alborn; Peter E Teal |
Related Documents
:
|
19766017 - Chemical ablation of the gallbladder with acetic acid. 15893787 - Chemical and biochemical generation of carbohydrates from lignocellulose-feedstock (lup... 9784327 - Effect of acetic acid on telomerase activity in cervical intraepithelial neoplasia. 5776527 - Assimilation and metabolism of exogenous organic compounds by the strict autotrophs thi... 20181007 - Ordering folate assays is no longer justified for investigation of anemias, in folic ac... 6123477 - Methionine degradation in candida utilis. |
Publication Detail:
|
Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S. Date: 2011-03-14 |
Journal Detail:
|
Title: Proceedings of the National Academy of Sciences of the United States of America Volume: 108 ISSN: 1091-6490 ISO Abbreviation: Proc. Natl. Acad. Sci. U.S.A. Publication Date: 2011 Mar |
Date Detail:
|
Created Date: 2011-03-30 Completed Date: 2011-06-10 Revised Date: 2012-05-07 |
Medline Journal Info:
|
Nlm Unique ID: 7505876 Medline TA: Proc Natl Acad Sci U S A Country: United States |
Other Details:
|
Languages: eng Pagination: 5455-60 Citation Subset: IM |
Affiliation:
|
Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture, Agricultural Research Service, Gainesville, FL 32608, USA. eric.schmelz@ars.usda.gov |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Antifungal Agents / chemistry, metabolism Colletotrichum / pathogenicity Diterpenes / chemistry, metabolism* Insecticides / chemistry, metabolism Insects / pathogenicity Molecular Structure Mucormycosis / microbiology Plant Diseases / microbiology Plant Growth Regulators / metabolism Rhizopus / pathogenicity Sesquiterpenes / chemistry, metabolism* Zea mays / chemistry*, microbiology, parasitology, physiology* |
| Chemical | |
Reg. No./Substance:
|
0/Antifungal Agents; 0/Diterpenes; 0/Insecticides; 0/Plant Growth Regulators; 0/Sesquiterpenes; 37297-20-4/phytoalexins |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Identifying governance strategies that effectively support ecosystem services, resource sustainabili...
Next Document: Compensatory network changes in the dentate gyrus restore long-term potentiation following ablation ...